Conventionally known is a control device in a continuously variable transmission for a vehicle including a torque converter, wherein the control device employs a simulated step shift mode, wherein the simulated step shift mode is configured to set a target input rotational speed so as to repeat gradual increase and rapid decrease of a transmission input rotational speed during acceleration of the vehicle, and thereby vary a transmission ratio in a stepwise manner (see a patent document 1, for example).
However, if the simulated step shift mode is performed at low oil temperature in the conventional vehicular continuously variable transmission control device, the transmission input rotational speed becomes unstable, for example, because an engine rotational speed does not fall but remains high even when an upshift is performed. This causes a problem that a driver may feel uncomfortable when the simulated step shift mode is employed for shifting at low oil temperature.